Secret Distribution System and Secret Distribution Method of Files

3. The secret distribution system of files according to claim 2, wherein the threshold value for the number of the plurality of divided files required for restoration of the original file is set in advance in the file information management unit of the sending user terminal, and is managed in the file information management unit of the management server.

4. The secret distribution system of files according to claim 1, wherein the management server includes a one-time password generating unit that creates a time-limited one-time password that is used in a case where opening is performed when the Internet is not connected, and the sending user terminal and the receiving user terminal include a one-time password analyzing unit for analyzing the one-time password.

5. The secret distribution system of files according to claim 1, wherein the restoration information added to the plurality of combined files includes an access right, a deadline for opening, and the threshold value for the plurality of divided files.

6. The secret distribution system of files according to claim 1, wherein an application for opening the plurality of combined files is any of the self-extracting type, the disk configuration browsing software type, and the virtual disk mount type.

9. The secret distribution method of files according to claim 7, wherein the restoration information added to the plurality of combined files includes an access right, a deadline for opening, and the threshold value for the plurality of divided files.

10. The secret distribution method of files according to claim 7, wherein an application for opening the plurality of combined files is any of the self-extracting type, the disk configuration browsing software type, and the virtual disk mount type.

11. The secret distribution method of files according to claim 10, wherein a variable-length gap is embedded between the plurality of combined files and the application for opening.